Glass paneling with a sublimated image and process for making the same

ABSTRACT

Disclosed herein is a glass sheet substrate and process for making the same with a first wear surface, an obverse, second surface including a thermoset image receiving coating having a complete, unitary sublimated ink image that is viewable with minimal loss of resolution and clarity from the first side through the thickness of the glass sheet substrate.

I. RELATED APPLICATIONS

This is a continuation-in-part application of Ser. No. 10/860,083 filedJun. 3, 2004 and a continuation of Ser. No. 11/447,266 filed Jun. 6,2006, now U.S. Pat. No. 7,504,361.

II. FIELD OF THE INVENTION

This invention relates generally to glass sheets having a complete imageformed on the surface. More particularly, the current invention relatesto multicolored-imaged glass sheets and a process for making the samewhere the glass sheets are of sufficient dimensions to accommodate anentire image, to provide sublimated, multi-colored images, to maintainintegrity and stability of the image in ambient conditions. Such glasssheets may be used in structural contexts such as doors, windows, orflooring, or non-structurally, such as decorative wall panels, roomdividers and the like, which permit visual access of the high resolutionsublimated images through the glass sheets.

III. BACKGROUND OF THE INVENTION

It is known in the art to place images on substrates, such as floors,walls doors, non-structural panels, furniture and the like. It is alsoknown in the art to use sublimation to place these images onto thesesubstrates. However, conventional processes and techniques requireplacement of the sublimated image on the exposed, wear surface of thestructural member, such as an upper floor surface or a utility surfaceof a table top. Also, conventional techniques rely on materials such aslaminated plastics which have a tendency to deform as a result ofrelatively lesser hardness and rigidity and, consequently, becomescratched and disfigured. To overcome such issues, it is conventional tocoat the images and substrates with a protective layer in an attempt toenhance the wearability and longevity of the images.

For example, U.S. Pat. No. 4,452,604, U.S. Pat. No. 5,188,876, U.S. Pat.No. 4,232,076, U.S. Pat. No. 6,025,023, U.S. Pat. No. 6,482,285, U.S.Pat. No. 6,000,793, and U.S. Pat. No. 6,332,941 all disclose variousknown techniques of placing an image on an exposed, wear surface.Typically colored coated materials according to these teachings take theform of small pieces or tiles which are assembled into a desired mosaicpattern that must be laid down and affixed with considerable labor andeffort. Moreover, gaps between abutting pieces must be filled with awater resistant sealant which adversely impacts the aesthetics of theoverall image quality.

The above referenced art suffers from several additional shortcomings.For example, a color image imprinted or coated on an exposedexterior/wear surface which may or may not be covered by a protectivecoating typically degrades over time and differentially erodes due toexposure to ambient conditions and erosive forces, e.g., foot traffic,dropped utensils, etc. Materials selected as the substrate or carrier ofthe image, most typically plastics, whether coated or not with anabrasion-resistant layer, and even metals and ceramics, have a tendencyto wear, deform, scratch, and generally degrade. Also, where the priorart suggests or teaches placement of an image on an exposed wear surfaceintended for user contact, it follows naturally that the imagedsubstrate surface will be exposed to a greater amount ofdistress/abrasion/trauma. Even combining teachings from the prior art toaddress wear/erosion/traffic damage merely leads to the use ofprotective layers and or laminations, while perhaps serving to enhanceimage longevity, also cause degradation and/or distortion of imageresolution.

Relatively more expensive interior glass laser etching techniques havebeen suggested as a means to maximize image preservation by effectivelyimbedding the image in the glass sheet. However, such techniques arelimited essentially to monochromatic representations and requireexpensive equipment and precise control. Other known art disclosesalternative techniques for producing, for example, pixilated arrays onglass surfaces. One such multi-step process, described in U.S. Pat. No.5,981,112, contemplates repeated use of lift off procedures,mechanical/chemical polishing, and/or close space sublimation/etchingprocesses for each color.

Still other known art is directed to alternative approaches formulticolor image generation on glass. For example, U.S. Pat. No.6,336,723 describes generating a computer-controlled printer image onrelatively large sheets of glass. The process relies on light-fast inks(e.g., glass sintered powders with pigments/enamels) directly applied toa glass sheet which is then fired at in excess of 450° C.

Additional teachings relating to the manufacture of simulated stainedglass are identified in Sikorski, U.S. Pat. No. 6,357,103, which relieson adhering a laser printed, imaged/colored polyester film to glass withresin, preferably an epoxy.

To imprint vanity/custom images, photographs, children's art work, etc.,by sublimation onto relatively small ceramic surfaces, e.g., coffeemugs, plates, etc., is now well known. An effective sublimation-transferreceptor-surface coating and technique is described in Valenty, U.S.Pat. No. 5,234,983. This coating, Thermoglaze 2000 complies with the FDAguideline for food contact ceramic coatings. Thermaglaze 2000 isrecognized for providing hard, durable, scratch resistant, coatings thatprotect the integrity of underlying images on the ceramic surface.

What is needed then is a new type of substrate imaging technique thatprovides a long lasting, multicolored image of high resolution andclarity of on generally transparent surfaces even when exposed tosubstantial wear forces. The same is equally desirable in a form thatresults in the formation of a sublimated image that is viewable in adesired direction yet is protected from exposure, wear and traffic, suchas on a floor, table top, or door.

IV. SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to address andovercome the above-referenced problems with sublimated, multi-coloredimage structures, apparatus, and methods.

It is another object of this invention to provide a highly efficient andefficacious system for creating large, single-sheet decorative glassthat can be produced relatively inexpensively, with a minimum of laborand that possesses enhanced longevity.

Another object of this invention is to provide a glass sheet having asublimated image positioned on the opposite/obverse of the wear surfaceon a generally transparent unitary glass sheet dimensioned toaccommodate an entire multi-colored image.

Still another object of the present invention is to provide atransparent substrate having a properly orientated image such that theentire image is viewable through the glass sheet.

A further object of the present invention is to provide a floor having aglass section with a sublimated image positioned underneath the glassflooring section such that the image is viewable through the glassflooring section to one walking on the floor.

Yet another object of the present invention is to provide a door for abath or shower enclosure formed of a single glass section with asublimated image on the door surface so as to be readily viewable butalso to restrict visual access to the interior of the enclosure.

A further object of this invention is to permit production of a ruggedglass panel bearing a sublimated, customized, truthfully reproduced,image of any desired subject matter ranging from company indicia tofamily photographs on the obverse of the wear/exposed panel surface.

These and other objects are satisfied by a generally transparent andsubstantially clear glass sheet substrate comprising a first surface andsecond obverse surface, dimensioned to receive an entire imprintedimage, said first and second surfaces being spaced apart by thethickness of the substrate in a manner not to degrade resolution of asublimated image viewed therethrough, and an image positioned on thesecond surface and viewable from the first surface through the glasssheet. The glass substrate is preferably in the form of a single sheetdimensioned to receive the entirety of a multi-colored image which isapplied in a single application. The resulting multi-colored glassprovides clear viewing clarity of a crisp image without loss ofresolution, degradation, or distortion.

Exemplary uses of these glass sheets include floors and floor sections,walls, doors, and bathroom placement. Additionally the glass sheets canbe used as architectural, structural and decorative panels in and aroundswimming pools. The invention also contemplates use as kitchencountertops.

The glass sheets are of a commercial grade and can combine to fillcommercial applications on floors, walls, countertops, swimming pools,back splashes in kitchens, and the like. Placing the images on thenon-wear surface of the glass sheets overcomes longstanding problems,i.e., namely, the ability to perceive the image without distortion ordegradation and still maintain a high level of durability of the imageon a floor or other exteriorly exposed surface.

The invention also contemplates a new use of a known coating which isdescribed in Lewis, U.S. Pat. No. 6,265,029, the content of which isincorporated herein by reference in its entirety. That coating iscommercially available under the name “Satin Hardcoat” from CaliforniaHardcoating Company of Chula Vista, Calif. Applying this preferredcoating compounded with other constituents described herein coupled withlarge-format multi-colored images on a unitary glass substrate sheetunder controlled temperature, humidity, and environmental conditionsprovides a product satisfying objectives of the invention.

As used herein “transparent” is directed to the opacity characteristicof the glass and in generally intended to connote minimal scatter oflight passing therethrough. “Clear” as used herein is directed to thecolor of the glass, i.e., clear glass is colorless.

As used herein “substantially,” “generally,” and other words of degreeare relative modifiers intended to indicate permissible variation fromthe characteristic so modified. Such descriptive words are not intendedto be limited to the absolute value or characteristic which they modifybut rather as possessing more of the physical or functionalcharacteristic than their opposite, and preferably, approaching orapproximating such a physical or functional characteristic.

In the following description, reference is made to the accompanyingdrawing, which is shown by way of illustration to the specificembodiments in which the invention may be practiced. The followingillustrated embodiments are described in sufficient detail to enablethose skilled in the art to practice the invention. It is to beunderstood that other embodiments may be utilized and that structuralchanges based on presently known structural and/or functionalequivalents may be made without departing from the scope of theinvention.

V. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of a glass sheet of exaggeratedthickness providing a unitary substrate dimensioned to receive an entiresublimated image in accordance with the current invention.

FIG. 2( a) shows a front view of an embodiment of a glass sheet inaccordance with the current invention.

FIG. 2( b) shows a cross-sectional view of FIG. 2( a) along line2(b)-2(b).

FIG. 2( c) shows a back perspective view of the glass sheet embodimentshown in FIG. 2( a).

FIG. 3 shows a front view of an embodiment of a tabletop made inaccordance with the current invention.

FIG. 4 shows an alternate embodiment of a floor made in accordance withthe current invention having to provide an image.

FIG. 5 shows an example of a glass floor made in accordance with thecurrent invention.

FIG. 6 shows an example of a glass sheet made in accordance with thecurrent invention used as a bath boundary.

VI. DETAILED DESCRIPTION OF THE DRAWINGS

Referring generally now to FIGS. 1-6, a glass sheet substrate made inaccordance with the current invention is generally shown and designatedby the numeral (10). The glass sheet comprises a first, exposed or wearsurface (12), a second oppositely facing (obverse) non-wear surface(14), a thickness (16), and a sublimated image (18) formed on the secondsurface (14).

The image (18) is positioned such that a viewer (not shown) of the glasssheet (10) is able to view and comprehend the image (18) when viewingthe glass sheet (10) from the first surface (12). The image (18) isviewable without distortion or degradation through the thickness (16) ofthe glass sheet (10).

The image (18) is sublimated onto the second surface (14) in accordancewith the process described herein. The sublimated image (18) isorientated and positioned on the second surface (14) such that it isproperly viewable through the thickness (16), as best illustrated inFIGS. 2( a)-2(c).

In a preferred embodiment the glass sheet substrate (10) is a boundaryfor a washing facility (26). For example, the washing facility (26) canbe a shower stall, shower door, bath wall, bath floor, bath tub, in abathroom, and the like. The glass sheet can also be attached to a wallas an accent or decorative panel wherein the second surface (14) isaffixed to the wall such that the image (18) is protected from theenvironment in which the wall is located.

FIG. 2( b) illustrates the cross-sectional view of a panel particularlysuited for flooring. In FIG. 2( c), the wear surface (12) includessurface texturing (22) preferably formed integrally during manufactureof the glass but may be formed later using by one of many available,appropriate clear, transparent, non-image degrading coatings.Preferably, as a result of the texturing, the wear surface (12)possesses a coefficient of friction greater than 0.40 to facilitatelocomotion/walking. Additionally, the glass section (10) may include abacking coating or material (24) sandwiching the sublimated image andthe second glass surface (14). The purpose of this coating is to improveimage contrast and, therefore, visibility of the sublimated image (18).This backing material is preferably white in order to enhance the image(18).

FIGS. 3, 4, and 5 represent decorative floor paneling sheets inaccordance with the invention. In these embodiments, preferably, thefloor (20) does not include an abrasion or wear-resistant layer orcoating disposed on the wear surface (12) to avoid degradation of theimage viewing but includes the non-image degrading friction enhancinglayer (22). Ideally, the invention dispenses with the need for thewear-resistant layer due to the inherent hardness and scratch-resistanceof the glass itself as well as the fact that the sublimated image (18)is formed on the opposite, non-wear side (14).

Additionally, the sublimated image on the proximately positioned glasssection (10) provides an uninterrupted, unitary image that mayincorporate a decorative framing/border/boundary (32) comprised of othermaterials providing strength and structure to the glass floor (30). Asillustrated in FIG. 5, the invention contemplates an attractive,customized flooring panel for an entryway that features a large-formatcompany name/logo or other desired information.

As a final illustration of potential applications of the invention in ahousehold context, FIG. 6 depicts a shower stall (26) including aunitary, single imaged door panel (10). In one embodiment, themulti-colored image also serves as a privacy screen for an occupant ofthe shower, particularly when the sublimated image is formed inconnection with the below-described high-contrast coating.

Details of preferred components for use in connection with the inventionare now described. Preferably, the glass used herein is tempered, thatis pre-stressed, and may even be safety glass. The glass may beformulated using known additives to enhance desirable physicalproperties such as breakage resistance, UV light degradation resistance,etc. Preferably, the glass substrate sheet (10) has a thickness of atleast 0.25 in (6.3 mm) but may have a greater thickness depending on theintended use. As a practical matter, the thicker the glass sheet, theheavier it is and the more costly. However, in the context of thisinvention, so long as the optical properties of the glass composition donot interfere or degrade the image being viewed through the glass sheet,the thickness is not limited.

In the context of architectural/structural applications, preferably theglass used as the glass substrates/sheets (10), preferably meets ANSIand ASTM standards for commercial wall and floor applications. The glasspreferably exhibits properties adequate to meet the following standardsthat comply with those established for ceramic tile flooring by the TileCouncil of America:

a. ASTM C1026: Freeze-Thaw Tiles showed no evidence of freeze-thawdamage after completing 15 cycles of freeze-thaw. b. ASTM C1028: StaticCoefficient of Friction Dry = 0.86 Wet = 0.52 c. ASTM C373: WaterAbsorption Rate 0.37% = impervious d. ASTM C650: Resistance to ChemicalSubstances Not affected by the following: Acetic acid 3% & 10%; Ammoniumchloride, 100 g/L; Citric acid solution, 30 g/L & 100 g/L; Lactic acid,5%; Phosphoric acid, 10%; sulfamic acid, 3% & 10%; Swimming PoolChemicals = Sodium hypochlorite solution, 20 mg/L; Acids & Bases =Hydrochloric acid solution, 3% & 18%; Potassium hydroxide, 30 g/L & 100g/L e. ASTM C485: Warpage of Tile Edge warpage: −.02%; Diagonal,warpage: 0.00% f. ASTM C499: Dimensional Variation Facial dimensions andthickness of tile Average difference of 0.020 inches g. ASTM C502:Wedging of Tile Average percent wedging was 0.03% h. ASTM C648: BreakingStrength Average breaking strength is 1931 lbf i. Mohs Scratch 5 (1-talcto 10-diamond) Hardness

Such glass sheets possess the physical characteristics necessary to meetbasic requirements as use for flooring. The substrate may also be formedfrom known silicate-based glass substitutes such as polycarbonate glassbut at an understandably greater cost.

The preferred coating for use in the context of this invention is amixture of a liquid thermosettable, condensation co-polymerizedacidic-colloidal silica sol and the like withmonomethyltrimethoxysilanes (Satin Hard Coat) with blockedpolyisocyanate/polyurethane epoxy resins (Thermoglaze 2000 from Analyze,Inc. of Chandler, Ariz.). The preferred mixture is a 3 to 1 ratio ofThermoglaze to Satin Hard Coat. The resulting coating provides anexcellent color-sublimation medium that adheres strongly to thesubstrate and provides a water-proof, abrasion-resistant surface. SatinHard Coat is fully described in U.S. Pat. No. 6,265,029, which, asindicated above, is incorporated by reference herein. ThermoGlaze 2000is described in Valenty, U.S. Pat. No. 5,234,983, the content of whichis also incorporated by reference herein.

The Satin Hard Coat mixture may be applied by conventional applicationtechniques such as roller coating, spray coating, curtain coating andthe like. Preferably, the resulting layer has a thickness ofapproximately 2 mil and is allowed to cure in an oven for about 15minutes at a temperature of 390° F. (199° C.). Preferably, the entirecoated substrate is heated at the same time in a large oven, but theinvention also contemplates use of a conveyor oven where the sheets moveinto and out from the temperature controlled oven at a selected rate.

The curing conditions optimally are conducted in a low-humidity,substantially dust-free environment where the temperature changes aregradual. In one exemplary arrangement, an automatic conveyor transportsthe coated glass sheets over a long path which essentially comprisesthree distinct segments: a temperature ramp-up segment, a thermal curingsegment, and a cool-down segment. In the case of a 100 ft (30 m) line,the ramp-up segment is about 30 feet (9.1 m) where the temperature rampsup slowly from ambient to 400° F. (204° C.) in a period of 20 minutes.The first 10 feet (3 m) of the ramp-up segment is not heated to give thecoating a chance to flash at temperatures at ambient and above. As theconveyor moves the coated substrate further into the heat tunnel, andinto the thermal curing segment, the temperatures increase graduallyover every 5 feet (1.5 m) to provide an opportunity for solvents withinthe coating to differentially flash. For example, where the temperatureis increased 50° F. (28° C.) degrees every 5 feet: (1.5 m) commencing atambient ˜77° F. (25° C.), 125° F. (52° C.), 175° F. (80° C.), 225° F.(107° C.), 275° F. (135° C.), 325° F. (163° C.), 375° F. (190° C.) andto then 400 (204° C.) in the last oven segment of 10 feet (3 m) beforeexiting to the cool down segment. The cool-down segment incorporatescooling fans to advance temperature reduction to ambient (roomtemperature). While not limited to particular equipment, the practice ofthe invention contemplates utilization of a continuous conveyorproviding for coating of the glass sheet substrate with the sheetheating and cooling via large conveyor systems of a length of up to up150 feet (45.7 m) and including heat tunnels having a width of at least4 feet (1.2 m) in order to meet the requirements for continuous largescale processing contemplated by the invention.

After cooling to ambient temperature, preferably within about 20minutes, by use of fans the satin finish coating is ready to accept animage. Application to the now-cured coated substrate of appropriateimage-generating paints/dyes for sublimation may be accomplished usingconventional, known methods, e.g., hand painting, silk screening,airbrush spraying, laser printing, dye sublimation carrier media, etc.

If it is desirable to produce an image having a greater visible contrastrather than a satin/matt type finish appearance, the above-describedcured Satin Hard Coat coating may be substituted by a Thermoglaze-Silanemixture. That mixture is a 5:1 ratio of the Thermoglaze to an aminosilane such as Silquest 1110 available from GE Silicones of Danbury,Conn., which is applied to the substrate as above but cured at aslightly lesser temperature (380° F./194° C.). After cooling, a furthercoating is applied which is composed of a termixture of Thermaglaze2000, Satin Hard Coat, and Powdered Titanium Dioxide (TiO₂) in a 20:5:2weight ratio. That termixture is applied in a similar fashion to theabove-described satin finish coating, i.e., by spray, roller, or curtaincoating to a thickness of 2 mils which is cured for 15 minutes at thetemperature of 380° F. (194° C.). After cooling, the substrate with thehigh-contrast white backing coating is then imprinted for sublimation.

Also this invention contemplates addition to the Satin hard Coat coatingof effective amounts of desirable heat stable agents such as antifungaland antibacterial additives to the coating mixture. For example, addinga small amount of a fungicide in the context of high-humidity/bathroomuse provides resistance to mold growth. For example, in the context ofnon-food use, adding a small amount (e.g., 1 gm/4 liters) of thethiazolyl substituted benzimidazole antifungal agent Metasol TK-100(Lanxess), does not adversely impact the coating characteristics of theSatin Hard Coat compositions and enhances antifungal capability.

The foregoing describes the process for preparing the substrate forreceiving the multi-colored image. To that end, the sublimationinks/dyes preferred for use in connection with creation of the imagecontemplated by this invention are conventional sublimation dyes/inksavailable from Sawgrass Technologies, Inc. of Mount Pleasant, S.C., suchas those, for example, described in connection with the processdisclosed in U.S. Pat. No. 5,488,907 and available under the markSublijet®. Images may be selected from sources ranging from professionalimage catalogs including reproductions of famous masterpieces, images ofhistorical figures and documents, images of animated characters,original works of corporate graphic arts, to personal digital familyphotographs and personal artwork. Preferably, to maximize accurate andtruthful reproduction, the image is achieved computer technology andmore particularly, using a dot matrix printer or laser type printercharged with the above described sublimatable inks.

Alternatives to the forgoing should be readily apparent. For example,the substrate need not be a conventional flat sheet but may be curved,convex, or concave. Consistent with objectives of the invention, acomplete sublimated image may be formed on a select surface of thenon-flat surface by may require application of the coating and image inkby hand/spraying rather than a preferred, automated process.

Given the foregoing, it should be apparent that the specificallydescribed embodiments are illustrative and not intended to be limiting.Furthermore, variations and modifications to the invention should now beapparent to a person having ordinary skill in the art. These variationsand modifications are intended to fall within the scope and spirit ofthe invention as defined by the following claims.

I claim:
 1. A custom imaged glass panel, comprising: a generallytransparent glass sheet substrate comprising a first surface, andsecond, oppositely facing surface defining a surface area dimensioned toreceive an entire sublimated multi-colored image, said first and secondsurfaces being spaced apart by the thickness of the substrate selectedto minimize image resolution degradation; an image contrast enhancer onsaid second surface; an image receiving coating on said second surface;and an entire image disposed on the second surface, said image havingbeen formed using ink sublimated within said coatings and said imagebeing viewable without substantial degradation from the first surfacethrough the thickness of the glass sheet substrate; where the imagereceiving coating includes a condensation co-polymerizedacidic-colloidal silica sol.
 2. The custom imaged glass panel of claim 1where the image receiving coating has a thickness of 2 mils.
 3. Thecustom imaged glass panel of claim 1 where the image contrast enhanceris a coating comprises a mixture of blocked polyisocyanate/polyurethaneepoxy resin and a powdered contrast agent in a 10:1 ratio.
 4. The customimaged glass panel of claim 3 where the image contrast enhancer includestitanium dioxide.
 5. The custom imaged glass panel of claim 4 where theimage contrast enhancer has a weight ration of 10:1 of the blockedpolyisocyanate/polyurethane epoxy resin to the powdered titaniumdioxide.
 6. A custom imaged glass panel, comprising: a generallytransparent glass sheet substrate comprising a first surface, andsecond, oppositely facing surface defining a surface area dimensioned toreceive an entire sublimated image, said first and second surfaces beingspaced apart by the thickness of the substrate selected to minimizeimage resolution degradation; an image contrast enhancer on said secondsurface; an image receiving coating on said second surface; and anentire image disposed on the second surface, said image having beenformed using ink sublimated within said coatings and said image beingviewable without substantial degradation from the first surface throughthe thickness of the glass sheet substrate; where the image receivingcoating is composed of 1 part liquid thermosettable, condensationco-polymerized acidic-colloidal silica sol withmonomethyltrimethoxysilanes to 3 parts blockedpolyisocyanate/polyurethane epoxy resin.
 7. The custom imaged glasspanel of claim 6 where the image receiving coating is a termixture of a)blocked polyisocyanate/polyurethane epoxy resin, b) liquidthermosettable, condensation co-polymerized acidic-colloidal silica solwith monomethyltrimethoxysilanes, and c) powdered Titanium Dioxide(TiO₂) in a 20:5:2 weight ratio.
 8. The custom imaged glass panel ofclaim 1 where the ink sublimates and the image receiving coatingthermosets at a temperature of about 200° C.
 9. The custom imaged glasspanel of claim 6 where the ink sublimates and the image receivingcoating thermosets at a temperature of about 200° C.
 10. The customimaged glass panel of claim 1 where the substrate is clear and has athickness of at least 6.3 mm and where the first and second surfaces areevenly spaced apart in parallel planes.
 11. The custom imaged glasspanel of claim 1 where the first and second surfaces are the same size.12. The custom imaged glass panel of claim 1 where the image receivingcoating further includes a heat stable compound selected from the groupconsisting of mold inhibitors, antibacterial agents, and anti-fungalcompounds.
 13. The custom imaged glass panel of claim 5 where the imagereceiving coating further includes a heat stable compound selected fromthe group consisting of mold inhibitors, antibacterial agents, andanti-fungal compounds.
 14. The custom imaged glass panel of claim 7where the image receiving coating further includes a heat stablecompound selected from the group consisting of mold inhibitors,antibacterial agents, and anti-fungal compounds.